Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
// Java Program that is been setup in Sublime Text
// for Competitive Coding

// Importing input output classes
import java.io.*;
// Importing Scanner class from java.util package
import java.util.Scanner;
import java.util.*;
// Main Class
public class hello {

	// Main driver method
	public static void main(String[] args) {

		// Setting up the input stream
		// You can use buffered reader too
		Scanner scn = new Scanner(System.in);

		// If You Are Running Your Code
		// in Sublime Text then set The
		// System Out to output.txt and
		// Input Stream to input.txt
		// otherwise leave it as standard
		// ones for ONLINE JUDGE
		if (System.getProperty("ONLINE_JUDGE") == null) {
			// Try block to check for exceptions
			try {
				// Sets the Output Stream
				// to output.txt
				System.setOut(new PrintStream(
				                  new FileOutputStream("output.txt")));

				// Change the input stream
				// to input.txt
				scn = new Scanner(new File("input.txt"));
			}

			// Catch block to handle the exceptions
			catch (Exception e) {
			}
		}

		// Your Code Start Here

		// scn input
		String inp = scn.nextLine();
		Set<Character> hash_Set = new HashSet<>();
		for (int i = 0; i < inp.length(); i++) {
			if (inp.charAt(i) >= 'a' && inp.charAt(i) <= 'z') {
				hash_Set.add(inp.charAt(i));
			}
		}
		// Print output
		System.out.println(hash_Set.size());
	}
}